The dynamic organization of dislocation structures: A simulation

The dislocation structures formed in metals during plastic straining usually build up characteristic bi- or three-dimensional patterns: tangles, walls, veins, subgrains, various kinds of more or less isotropic and more or less well-defined cellular networks. Several models have been proposed to describe such nonuniform and organized structures, in relation with theories of strain hardening or of the flow stress. It appears that in every practical case the relative weight of two competing factors must be examined. In the present study, the authors propose an approach by simulation which is rather neutral with respect to the main assumptions or approximations reported above. Only simplified situations, involving one Burgers vector, can be considered. This work aims at proving that dislocation patterns can have a dynamic origin, characterizing the parameters which promote self-organization, and checking a few experimental facts and testing empirical laws or possible approximations.